Explanation:
The star cataloged as
HD 189733
is a mere 63 light-years away.
Its location is indicated in this deep,
wide-angle image of the sky
centered on the northern constellation of Cygnus.
Considering the many bright stars, nebulae, and star clusters
in the region
more familiar to skygazers, HD 189733 may not seem to be
remarkable, but it is known to have at least one
hot, jupiter-sized
planet orbiting very close, with an impressively
short period of 2.2 days.
Because the planet regularly eclipses its parent star,
astronomers can study starlight that
passes directly through the planet's atmosphere and identify
molecules
through spectroscopy.
Following the discovery of water vapor in the planetary
atmosphere,
astronomers now report that
Hubble Space Telescope data
also indicates the signature of
methane (CH4).
The exciting result is the first detection of an
organic molecule on a planet orbiting another star.
Although HD 189733's planet
is considered too hot and inhospitable to support life,
the work is a step
toward measuring conditions and chemistry on other
extrasolar
planets where
life could exist.